Typical electronic mail (e-mail) systems utilize a mail server, often controlled by the Internet Service Provider (ISP) or other manager of email service, as well as a mail client located on each user's machine. The mail server typically has permanent access to the Internet, as well as other external networks and public data communications networks. The mail server stores and manages user electronic mails. Mail for each authorized user on the system is maintained within an individual storage architecture, commonly known as an inbox. FIG. 1 is a block diagram illustrating this type of design. A mail server 100 connected to a local area network (LAN) 102 may store incoming emails directed to the LAN, while another mail server 104 may operate as part of a public or private wide are network (WAN) 106. The mail server 100 may be periodically polled by desktop mail clients 108a, 108b, portable/handheld mail clients 110, and/or portable computer mail clients 112. A firewall 114 may be connected between the LAN 102 and the WAN 104. Desktop and laptop computers 116a, 116b may be connected to the WAN 104 via dial up 118 or dedicated 120 connections. Additionally, a desktop or laptop computer 122 and/or portable/handheld computing/communications device 124 may connect to the WAN 104 through a wireless connection 126a, 126b. 
Personal data management suites have grown in popularity in recent years, buoyed by the increase in the variety of portable devices capable of running such applications. A personal data management suite is a group of application programs that allows users to keep track of personal data, such as appointments, contacts, meeting reminders, task reminders, free form notes, etc.
Due to the wide variety of devices that run personal data management suites, it is not uncommon for users to maintain multiple copies of their personal data management database. A user may have an office desktop computer, a home computer, a laptop computer, a personal data assistant (PDA), and intelligent mobile telephone, etc., all of which could potentially store a copy of the database. Not only are there multiple copies of the database, but there are also multiple sources of changes to the database, as the user could change the database while at work, on the road, via an assistant, or the database could be changed through a workgroup event scheduler.
Multiple copies of the database and multiple sources of changes result in the requirement to periodically synchronize the database among the different copies. However, since the format of these databases and their content is not standardized, each application must provide its own proprietary synchronization process.
Current approaches for synchronization of personal data management databases include direct connection synchronization, and specific application database server synchronization. In direct connection synchronization, the two devices to be synchronized are directly connected. This may be via direct serial data link, Universal serial bus (USB), the Internet, parallel data connection, Infrared serial connection, radio data link, or any other one-to-one data connection. Both synchronizing devices contemporaneously operate with the compatible personal data management application and compatible proprietary synchronization procedures. FIGS. 2A and 2B are diagrams illustrating examples of direct connection synchronization. In FIG. 2A, the devices are located at or about the same physical location. The connection may be, for example, direct serial data link, USB, parallel data connection, etc. In FIG. 2B, the devices are connected through a public or private wide area network, such as the Internet. In both examples, the two devices must be concurrently running compatible database synchronization procedures.
In specific application database server synchronization, all databases are maintained on a proprietary application specific database server. All devices maintain local copies of the database, but perform a proprietary synchronization procedure with the database server. Here again, both the device and the server need to have contemporaneous operation to provide synchronization. FIG. 2C is a diagram illustrating an example of specific application database server synchronization. A master copy of the personal information databases resides on the proprietary database server 200, and each of the devices 202, 204, 206, 208 maintain a local copy of the database information.
However, not all users have the luxury of being able to rely on the availability/accessibility of such a proprietary application server. Instead, a user may only have access to standard electronic mail servers, especially when dealing with handheld-type devices. These electronic mail servers do not support the maintenance of such a centralized master copy of the databases. The electronic mail servers also do not support the proprietary synchronization procedures of these database applications. Additionally, even if the user does have access to a proprietary application server, such a system requires that the server be available 24 hours a day, which may be too much of a burden on the server.
Therefore, users of such personal data management suites must periodically ensure that each device be synchronized with all other devices that also carry the same database information.
Furthermore, there has been an increase in the use of high-powered laptop computers as desktop replacements. While this allows the user to take the laptop and its copy of the personal management database on the move, it also means the user cannot rely on the desktop computer as a permanently reachable device. Thus, it becomes even more difficult for a user to rely on a central accessible copy of the database.
What is needed is a solution that allows for the synchronizing of multiple copies of personal management data without requiring that the different devices that carry the data files be directly connected and without requiring the use of a proprietary application server. What is also needed is a solution that allows synchronization of personal management data without requiring contemporaneous operation of the synchronization partners.
Furthermore, it is sometimes desirable to be able to retrieve and respond to an email without downloading attachments to the email. For example, an email may be sent by a meeting organizer inviting attendees. The email may include attachments having documents pertinent to the meeting topic. An attendee receives the invitation email and responds with an acceptance. On acceptance, the attendee's calendar may automatically be updated with the meeting entry. However, the user may be on a device with little memory or a connection with low bandwidth, and thus may not want, or be able, to download the attachments. What is needed is a solution that allows for the receipt of and response to an email without necessitating the downloading of attachments to the email.